Filum terminale

The filum terminale ('terminal thread') is a delicate strand of fibrous tissue, about 20 cm in length, proceeding downward from the apex of the conus medullaris. It is one of the modifications of pia mater. It gives longitudinal support to the spinal cord and consists of two parts:Spinal cord. Spinal membranes and nerve roots.Deep dissection. Posterior view.Spinal cord. Spinal membranes and nerve roots.Deep dissection. Posterior view.Spinal cord. Spinal membranes and nerve roots.Deep dissection. Posterior view.Spinal cord. Spinal membranes and nerve roots.Deep dissection. Posterior view.Spinal cord. Spinal membranes and nerve roots.Deep dissection. Posterior view.Spinal cord. Spinal membranes and nerve roots.Deep dissection. Posterior view.Spinal cord. Spinal membranes and nerve roots.Deep dissection. Posterior view. The filum terminale ('terminal thread') is a delicate strand of fibrous tissue, about 20 cm in length, proceeding downward from the apex of the conus medullaris. It is one of the modifications of pia mater. It gives longitudinal support to the spinal cord and consists of two parts: The most inferior of the spinal nerves, the coccygeal nerve leaves the spinal cord at the level of the conus medullaris, superior to the filum terminale. However, adhering to the outer surface of the filum terminale are a few strands of nerve fibres which probably represent rudimentary second and third coccygeal nerves. Furthermore, the central canal of the spinal cord extends 5 to 6 cm beyond the conus medullaris, downward into the filum terminale. This article incorporates text in the public domain from page 750 of the 20th edition of Gray's Anatomy (1918)